JPH0811557B2 - Main frame of motorcycle - Google Patents

Description

TECHNICAL FIELD The present invention relates to a main frame of a motorcycle.

[Conventional technology]

As a conventional motorcycle having a pair of main frames symmetrically arranged on the left and right sides of a vehicle body, a pair of main frames made of a pipe material having a vertically long rectangular cross section is gradually expanded symmetrically from a head pipe at the front of the vehicle body. The vertical V-type engine is hung on the main frame below both mainframes while being extended to the rear, and both sides of the upper part of the engine are arranged so as to bypass the mainframes. Some V-type engines have a carburetor in the space formed between the front and rear cylinders.

[Problems to be Solved by the Invention]

In this way, when the main frames having a vertically long rectangular cross section are arranged at positions close to each other on the upper side of the engine, the upper part is covered with the fuel tank, so that, for example, adjustment work of the carburetor slow jet is required. When carrying out the adjustment, either a special jig must be inserted from the gap between the lower side of the main frame and the engine for adjustment, or the carburetor that requires adjustment must be removed for adjustment. There was an inconvenience that it took time and effort.

Therefore, a tool insertion hole is formed through the main frame,
A countermeasure for adjusting the carburetor through the tool insertion hole can be considered, but it is not preferable to form the through hole in the main frame because the rigidity of the main frame is reduced.

The present invention has been made in view of the above points, and an adjustment work of a carburetor arranged in a space between cylinders of a vertical V-type engine of a motorcycle while ensuring a required rigidity of a main frame. The purpose is to provide a main frame for motorcycles that can be easily operated.

[Means for solving the problem]

As a means for solving the above problems, the present invention includes a pair of main frames that symmetrically open from a head pipe in the front part of a vehicle body and that bypass the side of the upper part of the engine and extend to the rear of the vehicle body. In the motorcycle, the main frame integrally has both side walls and a reinforcing wall that divides the inside of the main frame into a plurality of parts, and corresponds to the adjusting screws of the carburetor disposed on the engine on both side walls of the main frame. A carburetor adjusting tool insertion hole that penetrates in a substantially extended direction of the axis of the adjusting screw is provided at the position.

[Work]

With this configuration, when adjusting the carburetor, a general-purpose tool such as a screwdriver is inserted through the carburetor adjustment tool insertion hole on the side wall of the main frame arranged so as to surround the side of the carburetor, and the adjustment screw is operated. This is easily achieved. Also, while the carburetor adjustment tool insertion hole is formed through the main frame, the internal reinforcing wall formed integrally with the main frame
The man-hours required to manufacture the frame can be reduced, and the required rigidity can be secured for the main frame.

〔Example〕

An embodiment in which the present invention is applied to a motorcycle having a vertical V-type 4-cylinder engine will be described below with reference to the drawings.

1 and 2 show a motorcycle according to an embodiment of the present invention with a seat, a cowling, an instrument and the like removed, wherein the motorcycle 1 rotatably supports a front wheel 2 between its lower ends. A front fork 4 having a handlebar 3 at its upper end is steerably supported by a head pipe 5. The head pipe 5 includes a pair of main frames 6
Of the head pipe gusset 7 is connected.
It is reinforced by.

This pair of main frames 6 has a vertically-oriented rectangular cross section of "eye" shape in which both side walls 6a, 6a and two reinforcing walls 6b, 6b partitioning the inside of the main frame 6 into three spaces are integrally formed ( (See FIG. 2). It is a closed hollow shape using an aluminum extruded material and has a gradual symmetry from the head pipe 5 in order to incline so that the rear side of the vehicle body becomes lower and to secure a housing space in the width direction of the engine. The main pipes 6 are expanded and extended to the rear of the vehicle body, and the separated rear end sides of both main frames 6 are connected by determining the width by a cross pipe 8 and pivot plates 9 are attached to the rear ends of both main frames 6, respectively. A rear fork 12, which rotatably supports a rear wheel 11, is supported on a pivot shaft 10 supported between both pivot plates 9 so as to be vertically swingable.

In addition, on the upper surface of both main frames 6 in the substantially center of the vehicle body,
A seat rail 13 is provided so as to be inclined so that the rear of the vehicle body becomes higher, and its rear portion is supported by a seat gusset plate 14 extending above each pivot plate 9, and the rear fork 12 is a rear suspension.
Suspended by 15 so that it can be buffered.

The vertical V-type four-cylinder engine 16 is hung on the front side of the engine 16 via the pair of engine hangers 17, and the rear side of the body on the both main frames 6 via the pair of pivot plates 9. Hold and arrange, vertical V
Front cylinder part 16a provided with two front cylinders of the engine 16
The upper part of the rear cylinder 16b, which has two rear cylinders, and the upper part of the rear cylinder 16b.
Fuel tanks 25 are fixedly installed on the upper surfaces of both main frames 6 so as to project from the space to the information.

In front of the engine 16, a radiator 18 is provided so that its upper portion is suspended by the head pipe gusset 7, and its middle portion and lower portion are supported by the engine 16 via link rods.

Two front cylinder exhaust pipes 19 are provided in the exhaust holes of each cylinder formed in the front cylinder part 16a of the engine 16 on the front side of the vehicle body, and two front cylinder exhaust pipes 19 are formed in the rear cylinder part of the rear cylinder part 16b. 2 rear cylinder exhaust pipes
20 are connected to each other, and the both exhaust pipes 19 and 20 are connected to the primary merging pipes 21 and 21 at the rear of the engine 16 respectively to merge them, and then they are merged into one by the secondary merging pipe 22, It is connected to an exhaust pipe 24 having a muffler 23 at its end.

On the other hand, in the space formed between the front cylinder portion 16a and the rear cylinder portion 16b of the engine 16 which is vertically installed in the V shape,
A pair of carburetors 26 for sending an air-fuel mixture to each combustion chamber of the front cylinder part 16a of the engine 16 which is a cylinder, and a carburetor 27 for sending an air-fuel mixture to each combustion chamber of the rear cylinder part 16b are respectively arranged. Heads of adjusting screws 26a and 27a for adjusting the fuel supply amount of the slow jet for discharging fuel from the float chamber (not shown) during low speed operation of the engine 16 are provided on the outer sides of the vehicle body on the outside of the vehicle. And the carburetor 2 of the rear cylinder portion 16b.
The head position of the adjusting screw 27a of 7 corresponds to the inner surface of both main frames 6.

Carburettor adjusting tool insertion holes 28 are formed in both side walls 6a, 6a of the main frames 6 at positions corresponding to the heads of the adjusting screws 27a in the axial extension direction of the adjusting screws 27a. .

In this way, by forming the carburetor adjustment tool insertion hole 28 at a predetermined position on both side walls 6a, 6a of each main frame 6 that surrounds the side of the carburetor 27, the adjustment frequency of the carburetor adjustment is relatively low. Many slow jet adjustments can be easily done with a tool such as a screwdriver while the carburetor is still attached.

Further, while the carburetor adjusting tool insertion holes 28, 28 are formed through both side walls 6a, 6a of the main frame 6, the reinforcing walls 6b, 6 partition the inside of the main frame 6 into three spaces.
By integrally forming b on both side walls 6a, 6a, it is possible to reduce the number of steps for manufacturing the frame, and at the same time, the main frame 6
It is possible to secure the required rigidity.

In this embodiment, as the main frame 6,
The case where an aluminum extrusion molded product having a vertically elongated rectangular cross section having two reinforcing walls 6b, 6b is used has been described, but the inner reinforcing wall has one vertically extending "Sun" shape. It may be rectangular, or can be applied to the case where a member having a large vertical width such as a vertically long oval is used, and the main part of a motorcycle equipped with an engine other than the vertical V-4 cylinder engine. It can also be applied to frames.

〔The invention's effect〕

As described above, the present invention integrally forms the pair of both side walls of the main frame and the reinforcing wall that divides the inside of the main frame into a plurality of parts, and adjusts the carburetor adjusting screw disposed on the engine upper part of the both side walls of the main frame. Since a carburetor adjustment tool insertion hole that penetrates in the direction substantially extending the axis of the adjustment screw is provided at the position corresponding to, there is no need to remove the carburetor during the carburetor adjustment work, and the carburetor remains attached. Can be easily performed using a general-purpose tool such as a screwdriver, and a dedicated jig for adjustment work, which has been required in the past, is not required.

Moreover, although the tool insertion hole is formed through the main frame, the internal reinforcing wall integrated with the main frame can reduce man-hours for manufacturing the frame and secure the required rigidity to the main frame. .

[Brief description of drawings]

1 and 2 show one embodiment of the present invention.
FIG. 1 is a side view showing a motorcycle equipped with a main frame according to the present invention, and FIG. 2 is a sectional view taken along line II-II of FIG. 1 ... Motorcycle, 5 ... Head pipe, 6 ... Main frame, 6a ... Side wall of main frame 6, 6b ... Reinforcing wall in main frame 6, 9 ... Pivot plate, 12
...... Rear fork, 13 …… Seat rail, 16 …… Engine, 16a …… Front cylinder part, 16b …… Rear cylinder part,
17 …… Engine hanger, 25 …… Fuel tank, 2
6,27 …… Carburetor, 26a, 27a …… Slow jet adjustment screw, 28 …… Carburetor adjustment tool insertion hole

Claims (1)

[Claims] 1. A motorcycle comprising a pair of main frames which are symmetrically opened from a head pipe in the front part of a vehicle body and which bypasses a side of an upper part of an engine and extend rearward of the vehicle body.
The main frame is integrally formed with both side walls and a reinforcing wall that divides the inside of the main frame into a plurality, and at positions corresponding to the adjusting screws of the carburetor arranged on the engine upper part of the both side walls of the main frame, A main frame for a motorcycle, comprising a carburetor adjusting tool insertion hole that penetrates in a direction substantially extending the axis of the adjusting screw.